This invention relates to a camera for taking photographs by operating photoflash means and data photographic means with a single battery.
As already known, there are cameras provided with means for recording data such as date of photographing other than any object. Pictures can be taken by mounting photoflash means including a battery and being detachable on such cameras for flash photography or recording data.
For cameras incorporating photoflash means may be provided with data recording means, which has a battery and can be mounted on such cameras.
In either case these prior-art cameras are not easy to carry and to operate for taking photographs due to their bulkiness and weight increased by mounting separate photoflash means and/or data recording means. For this reason, it is desirable to make easier maintenance of cameras or change of batteries by reducing the number and type of such batteries and to make less heavy the weight of cameras by making them more compact with such arrangement that at least photoflash means and data recording means can be operated with a single battery for taking photographs. When a camera thus arranged is used for taking a picture by operating both of photoflash means and data recording means, preparatory operation for the next flashing or charging a main capacitor through a step-up circuit is started automatically upon completion of the flash operation of the photoflash means. The terminal voltage of the battery right after the start of charging the capacitor drops suddenly and greatly due to its large electrostatic capacity charged with high voltage produced by oscillating operation. It takes a long time more than 10 seconds before the terminal voltage of the battery is restored after charging is finished. Time required for recording data in the data recording means is set for one-eight second, for instance, which is longer than exposure time, one-thirtieth second, for instance, for flash photography. As a result, even when the data recording means is started prior to the flash operation of the photoflash means, a sudden change may occur in the terminal voltage of the battery, as described above. This causes faulty operation of the data recording means or great reduction in the luminosity of a light emitting member such as a lamp for recording data, and consequently such data cannot be photographed on film with a proper exposure.